Exemplary embodiments of the present invention relate to a method for assembling motor vehicles.
It is commonly known from the series production of vehicles, in connection with the shell production and the subsequent coating of the respective shell bodies, to equip these with a respective interior installation in a main assembly line of the final assembly. Here, the bodies are guided through the main assembly line by means of corresponding conveyance and transportation technology. In this instance, the dashboard, the seating units, the central console, the pedals, the steering column and the interior trim, for example, are assembled as large modules. In parallel with the final assembly of the interior installation, a pre-assembly of the chassis and drive train typically takes place in the main assembly line, wherein these components are typically assembled and transported on a separate conveyance means. After the respective shell of the personal motor vehicle has been equipped with the interior installation in the main assembly line or final assembly, the so-called “marriage” now typically takes place, wherein the shell of the motor vehicle is connected to the corresponding chassis and drive train arranged on the separate conveyance means. It is only after it has passed through the main assembly line that the respective motor vehicle is equipped with vehicle wheels.
European Patent document EP 0 278 479 A2 discloses a modularly constructed personal motor vehicle, which consists of a front, central and rear module. These are completely pre-assembled along separate assembly lines. Here, the rear module has a rear frame with wheels pre-assembled thereon. This module is prefabricated and then connected to the other modules of a personal motor vehicle.
German Patent document DE 10 2004 038 487 A1 discloses a modularly constructed vehicle frame of a heavy goods vehicle. Diverse attachment parts are already pre-assembled on its front module. The configuration is such that it is completely pre-assembled and can then be connected to the main frame that supports the vehicle wheels. US Patent document 2009/0230665 A1 shows a similar concept with a frame-like front module with wheels pre-assembled thereon.
Furthermore, U.S. Pat. No. 4,257,158 discloses an assembly line for assembling buses in which a self-supporting undercarriage module in framework construction is connected to wheels that are pre-assembled thereon after the pre-assembly with a non-load-bearing construction of the bus.
PCT International Patent document WO 02/055364 A1 discloses a similar concept with a self-supporting undercarriage module and wheels assembled thereon for personal motor vehicles. European Patent document EP 0240 470 A1 discloses a highly similar undercarriage module.
European Patent document EP 1 454 817 A1 shows a vehicle with an auxiliary frame, which supports the engine and the suspension of the vehicle, which also contains the hubs for the front wheels, and which is connected to these parts together with the body.
Furthermore, PCT International Patent document WO 03/054500 A2 discloses a wheel module for a motor vehicle that is pre-assembled separately in its own assembly line and then fastened to the vehicle.
In turn, U.S. Pat. No. 5,090,105 discloses an assembly concept for a motor vehicle, wherein a non-load-bearing body superstructure is placed onto a self-supporting substructure, which already contains drive components and wheels.
Since the shell has to be guided through the main assembly line by means of corresponding conveyance and transportation technology for the equipment with the interior installation, and the chassis and the drive train have to be guided through their respective pre-assemblies, a considerable amount of expenditure for conveyance and transportation technology arises overall for the assembly of the motor vehicle. This entails not only high investment costs, but also a large space requirement in the assembly hangars. Furthermore, assembly with the existing conveyance and transportation technology is relatively inflexible.
Exemplary embodiments of the present invention are directed to a method for the assembly of motor vehicles of the type cited above, by means of which the expenditure for conveyance and transportation technology is considerably reduced.
In order to create a method of the type cited above, by means of which the expenditure for conveyance and transportation technology is considerably reduced in particular, provision is made according to the invention for the chassis to be equipped with vehicle wheels at least before one end of a main assembly line has been reached. Here, the motor vehicle is moved by external power or by its own drive after the chassis has been equipped with the vehicle wheels.
In other words, provision is thus made according to the invention for the motor vehicle to have vehicle wheels added to it at a far earlier point than has been typical to-date (which is typically after the main assembly line), in order to thus save at least one part of the conveyance and transportation technology, which is necessary for taking the weight of the motor vehicle and, if necessary, for moving the motor vehicle along. Since the motor vehicle can bear its own weight after the assembly of the vehicle wheels and at least roll, it is at least no longer necessary for the main assembly line to take the weight of the motor vehicle in the further procedure. This not only enables a considerable saving in conveyance and transportation technology with the consequential effects linked thereto, but a far more flexible assembly is also achieved. It is thus possible, for example, to carry out an offtake buffering of motor vehicles in a very flexible manner at an early point in time, and, if necessary, to store this temporarily before the further assembly is to take place. To that end, only one corresponding storage area is required.
In this case, the motor vehicle is alternatively moved by external power or even by its own drive after the vehicle wheels have been assembled. Here, externally powered is understood to mean that the motor vehicle is moved forwards with the aid of an external force—for example with the aid of a driverless transport system—but rolls on its own wheels. Thus, conveyance and transportation technology can at least be dispensed with, which must take a considerable part of the weight of the motor vehicle.
Alternatively, it is also possible for the motor vehicle to be moved by its own drive. For this, it is, however, necessary for the drive of the motor vehicle to already be made ready for operation. For an electric drive, the cabling to the battery of the vehicle and to the steering or to the respective control device must be produced. In an internal combustion engine, a driverless transport system is used for transportation through the main assembly line. An omission of connecting conveyance technology is also possible, such that a completely autonomous vehicle movement is provided.
A preferred embodiment here provides that the chassis is equipped with the vehicle wheels at least before the main assembly line, and indeed preferably in direct or quick conjunction with a connection of the chassis to the shell, which typically occurs in line with a so-called marriage. This preferably happens before the shell has the interior equipment added to it, such that the motor vehicle can preferably roll on its own wheels while the main assembly line is being entirely passed through, in which this has the interior installation added to it.
Finally, it has been shown to be advantageous if the movement of the motor vehicle onto the vehicle wheels takes place via a control device of the assembly line, in particular the main assembly line. Thus, the motor vehicle can be adjusted to the flow of the assembly line via external control signals.